Effect of rinsing with povidone-iodine on bacteraemia due to scaling: a randomized-controlled trial

Aim: To investigate rinsing with povidone-iodine on bacteraemia caused by ultrasonic scaling. Material and Methods: Sixty patients with gingivitis undertook a randomized, placebo-controlled trial in which 30 rinsed with 0.9% saline and 30 with 7.5% povidone-iodine for 2 min. before ultrasonic scaling of FDI teeth 31-35. Blood samples before and after 30 s and 2 min. of scaling were cultured by lysocentrifugation. Results: Oral bacteraemia occurred in 33.3% of the saline group and 10% of the povidone-iodine group. Regression analysis showed that rinsing with povidone-iodine was approximately 80% more effective than rinsing with saline in reducing the occurrence of bacteraemia, with a statistically significant odds ratio (OR) of 0.189 (95% confidence intervals, OR=0.043-0.827). There were 24 oral bacterial isolates in the saline group and 3 in the povidone-iodine group. Viridans streptococci comprised 11 of the isolates in the saline group and none in the povidone-iodine group. Bacteraemia magnitude was 0.1 colony-forming units /ml in the povidone-iodine subjects and 0.1-0.7 CFU/ml in the saline group. Conclusions: Rinsing with 7.5% povidone-iodine reduced the incidence and magnitude of bacteraemia and eliminated viridans streptococci from such bacteraemia. Povidone-iodine rinsing may be helpful for ultrasonic scaling of gingivitis patients at risk of infective endocarditis.